The advantages of cryogenic freezing

Cryogenic freezing (cryofreezing) is a method of freezing in which the food is exposed to an atmosphere below -60 °C through direct contact with liquified gases such as nitrogen or carbon dioxide.

Cryogenic technologies are generally used for food processing and food preservation many industries are use cryogenic technology in this time for better food quality and good products.

Compared to conventional freezing techniques, the cryogenic method has the following advantages: rapid freezing, inhibition of bacterial growth, limited dehydration, considerable reduction of quantitative losses, good retention of original quality attributes, maintenance of the appearance and taste of the food.

Cryogenic freezing helps minimize dehydration of the frozen items, while retaining item quality, texture, color, and, in the case of food items, flavor.

Using cryogenic systems one can avoid the large investment required for a compression refrigeration system, using only liquefied cryogenic fluid delivery from time to time.

Other advantages of cryogenic freezing: less energy requirement, low capital investment, minimal space requirement, maintenance space requirements, simplicity of operation, continuous in-line freezing, minimum off stream time.
The advantages of cryogenic freezing

Food processing: quick freezing

The two basic ways to achieve the freezing of foods are quick and slow freezing. The technical features of the quick freezing process are ultra rapid freezing at very low temperatures (-30 to -40 ° C) designed to bring the inside the product to a temperature of -18°C as quickly as possible. Rapidly frozen foods have a much longer storage life than foods stored in cold stores.

The products that are generally preserved by quick freezing are meat, fish, some vegetables such as peas, spinach, cauliflower, carrots, beans etc.

When the quick freezing process is used, these liquids solidify to form extremely fine crystals of ice, and the cellular structure is left intact, whereas, in the ordinary freezing process, where low temperatures are reaching more slowly, the texture of the product is altered.

In quick freezing, large quantity of food can be frozen in a short period of time.

Quick freezing is a method of increasing the shelf-life of perishable foods by subjecting them to conditions of temperature low enough to inhibit the oxidative, enzymatic and microbial changes, which are responsible for the changes in flavor and color of foods.

Quick freezing is ideal for producing good quality frozen foods. The food freezes immediately and keeps its shape and appearance.

Quick freezing is obtained by one of the following methods:
*Freezing Tunnel or Blast Freezer
*By Direct Contact with Metal Plate Surfaces maintained at Low Temperatures
*By immersion in (or by Spraying)  a Low Temperature Liquid
Food processing: quick freezing 

Cryogenic Freezing of food

Cryogenics is a term defined as the ‘science of low temperature’ and their effect on the properties of the matter.

The introduction of cryogenic gases in the early 1960’s as an alternative to improve freezing processes in the frozen industry was a major product quality and process improvement.

In food processing, cryogenics implies use of very low temperature materials for chilling and freezing.

This type of refrigeration differs from other procedure because it does not depend on external the low temperature production systems.

Cryogenic freezing with nitrogen is carried out by first passing the food through nitrogen vapor at about -50° C and then freezing the food by spraying the refrigerant directly onto the food.

Fish, meat, poultry, fruit, vegetables and bakery products can all be frozen in this way.

The extremely low temperature characteristics of cryogenic food provide the ultimate in chilling and freezing rates.

The physical properties of the cryogenic gases provided an important tool to help the food industry to improve the plant automation, versatility, efficiency and manufacturing cost.

Cryogenic Freezing of food